Let me be clear: I will defend "lines of code" as a metric useful for getting and order-of-magnitude estimate of the complexity of any given codebase. Anyone using it as a metric to determine how much to reward developers is just plain stupid.
[1] - http://www.folklore.org/StoryView.py?story=Negative_2000_Lin...
[2] - http://dilbert.com/strip/1995-11-13